another broken supp item?'(ardent canser son)

so i was minding my own busniss playing some solo q ,when i faced this karma with her twitch obv twtich got fed and one shotted the whole team over and over even tough it's just our botlane that lost but anyway,

i was playing gp, the game got to late game everyone got items n stuff , and that karma started one shotting ppl with 1 q while being unkillbable cuz of ms and a super hugh fking shield like for full hp,she only built rabadons deathcap and ardetn cancer as ap items , then she built "athene unholy grail" and finishing with redemtion and other supp items that dosnt have ap , the thing is she had 750 ap .. hello? no wonder she can one shot ppl like that i read that descreption of the item and it turn that it' gave 5 ap for every 25% base mana XDD ,

so she built a bunch of mana rengen supp item that also increade sheilds and heals by 20% for each and with ardent cancser and it was the ultimate cancer i have ever to play against ,is this a joke how the fuk a full supp items supp get acces to 780 ap ? https://imgur.com/jxAZUwA she also deals 40 k damage while twitch did 60 k https://imgur.com/cD7V1Y1